Ladder extension



April 1l, 1950 R. c. MAYBERRY 2,503,626

LADDER EXTENSION Filed March 5l, 1947 2 Sheets-Sheet 1 1130/3/96? C/g/eriy,

mwaaq April ll, 1950 R, c. MAYBERRY 2,503,626

LADDER EXTENSION A Filed March 51. 1947 2 Sheets-Sheet 2 y .-12mm2/mum111mm; 10 im fm im'. ll111|. mi?

i h /46 si 7 ,N I il L "was: 1 l 56 93'@ "x 53 ain? i@ Si 53 m2:

15 am Tg All.

,s\ 16 w 2.9 QC

l, gg

Patented Apr. 11,1950

UNITED STATES PATENT OFFICE LADDER EXTENSION Robert C. Mayberry,Statesville, N. C. Application March 31, 1947, Serial No. 738,427 7Claims. (C1. 228-63) The present invention relates to ladders and moreparticularly, to improved means :for adjustably connecting groundengaging legs to the stiles of the ladder.

An important object of the invention consists in associating with astile of a ladder, an attachment including a xed member preferably inthe form of a channel-shaped plate, and a slidable leg member having aground engaging shoe. Manually operating means extends transverselythrough the channel member and is operatively connected to the slidableleg to move the same longitudinally in order that the ladder may beeasily set up and the stile locked at the proper level, irrespective ofthe unevenness of the ground on which it is supported.

A further object is to provide the slidable leg member of theattachment, with a rack bar that extends lengthwise of the leg member.An operating shaft extends transversely through the attachment and isoperatively connected to the rack bar. Locking means in the form of aclutch mechanism is associated with the operating shaft so as to lockthe same and the rack bar in a xed position.

Another object consists in associating with the attachment a foot orground engaging member comprising revoluble discs having pointed teethextending radially therefrom and arranged selectively to be locked in afixed or non-rotatable position by means connected to the slidablemembers.

Other objects and advantages of the invention Will become apparent fromthe following description when taken in conjunction with theaccompanying claims and drawings.

Referring to the drawings in which are shown several preferredembodiments the invention may assume:

Figure 1 is a front view of a ladder constructed in accordance with thepresent invention.

Figure 2 is a detail side view of Figure 1.

Figure 3 is a sectional view taken substantially along the line 3-3 ofFigure 1 with the operating parts in their locked position.

Figure 4 is a detail view similar to Figure 3 with the operating partsmoved to their unlocked position.

Figure 5v is a sectional view taken substantially along the line 5-5of'Figure 3.

Figure 5a is a detailed perspective view of the slidable leg member andthe rack bar.

Figure 6 is a view similar to Figure 5 but with the adjustable legattachment removed from the` Stile.

Figure 7 is a front view of Figure 6.

Figure 8 is a sectional view taken substantially along the line 8-8 ofFigure 3.

Figure 9 is a sectional view taken substantially along the line 9-9 ofFigure 3.

Figure 10 is a view similar to Figure 9 with the parts shown in theirunlocked position, and

Figure 11 is a detail sectional view of a modified form of theinvention.

Referring to the drawings in which like numerals indicate like parts inthe several views, I0 designates the stiles or side rails of a ladderand II the spaced transverse rungs which are suitably connected to thestiles. The ladder may be made of wood or other suitable light, durablematerial and of such length and construction as to be used as a reladder or the like.

Each stile I6 of the ladder at the lower end thereof is shaped toreceive an extensible leg attachment which preferably includes asubstantially channel-shaped metal member I2 having an exposed face orbase I3 (Fig. 9) of substantially the same width as the stile I0 (Fig.2) and which is arranged to extend over the outer side of the stile.Extending inwardly from the base I3 are spaced flanges I4 which overlapthe front and rear sides of the stile and are secured thereto by thetransverse retaining bolts I5. The inner opposed faces or sides of thestiles I6 are free from contact with the channel member I2 and areprovided with aligned openings for receiving the rungs II. Within thechannel member I2 and between the flanges I4 is positioned a plate I6having depending flanges I1 (Fig. 9) which engage the adjacent flangesI4 and may be welded thereto as at I8 so as to provide an elongatedpassage or chamber I9 between the plate I6 and the base I3 for receivingan elongated flat slidable leg member 26 to which is medially andlongitudinally connected a rib 2l by the spaced screws 22. The outerface of the rib has transverse teeth 23 so as to form a rack bar. Theplate I6 has a centrally and longitudinally disposed offset portion 24which constitutes a housing for the rack bar 23 and is substantiallyco-extensive in length therewith. The slidable leg member 26 has itslower end projecting outwardly from the compartment or chamber I94 andpreferably carries a transverse bolt 25 which extends through anelongated vertical opening 26 in the lower portion of the member 20 soas to constitute a support for a foot or ground engaging member. Thisfoot preferably comprises a pair of disc-shaped members 2l and 28 thatare detachably connected through the retaining nut 29 to the bolt 25 andthe leg 29. Each of the discs 21 and 28 has a V-shaped notch 30 thatextends circumferentially around the outer periphery thereof and whichforms pairs of transverse aligned outwardly projecting prongs or teeth3| (Fig. 5) that provide sharp ground engaging means for insuring theladder being maintained in a fixed immovable position even on hardground such as cement or the like. The rack bar 23 has a pointed lowerend 32 arranged to fit in'to the groove or notch 30 and between theteeth 3| of the disc 21 so as to prevent rotation of the disc or thefoot member. A plate 33 extends between the discs 21 and 28 (Fig. 5) andis secured to the lower end of the rack bar 23 by the bolts 33. Theplate 33 extends parallel with the leg member and has an elongatedopening 25' through which extends the bolt 25. The inner surface or sideof the plate 33 is formed with a cut-out pointed portion 32 thatregisters with the pointed end 32 of the rack bar 23 so as to engage inthe peripheral teeth 3| of the disc 21, to lock the foot member inposition.

The inner surface of the lower end portion of the stile |2 is preferablycut out to form a centrally longitudinally extending groove 34 (Fig. 7)that is arranged to receive and is co-extensive in length with theoffset portion 24 of the plate I6 which houses the rack bar 23.Extending transversely of the stile I0 and through the flanges |4 of thechannel member l2 is a revoluble operating shaft 35 (Fig. 3) whichpreferably has its inner end 36 axially slidable in a tubular boss 31secured by the bolts 38 to a flange |4 of the channel member l2. Thetubular boss 31 is counterbored as at 39 (Fis. 4) and is of polygonalshape so as to slidably receive a complementary formed collar or clutchmember 40 fixed to the Shaft 35. A relatively wide pinion or cog wheel4| is keyed or otherwise secured to the shaft 35 so as `to mesh with theteeth 23 of the rack bar 2|, and the offset portion 24 of the plate I6,is cut away as at 42 (Fig. 4) so that the pinion or worm 4| may meshwith the teeth 23. A handle 43 is secured as at 44 to the outer exposedend of the shaft 35 so as to rotate the same and cause longitudinalmovement of the leg member 20 and the foot 21 in order to adjust thestile to the desired length for the purpose of insuring the ladder beingmaintained in a level position irrespective of the unevenness of theground on which it is supported. It will be seen that upon inward axialmovement of the shaft 35 from the position shown in Figure 4 to thatdisclosed in Figure 3, the polygonal collar 40 will move into lockingengagement with the recess 39 so as to prevent rotation of the pinion 4|and the rib or rack bar 2|, thus maintaining the leg 20 and the foot 21in a xed position relative to the ladder. Conversely, when the shaft 35is moved axially outward to free the collar 40 from engagement with therecess 39, the width of the pinion is such as to maintain the same inengagement with the teeth 23 of the rack bar 2| so that rotating of theshaft 35 through the handle 43 in one direction will move the leg member20 and its associated parts downward to lengthen the stile 2. Rotatingof the shaft 35 in an opposite direction will shorten the length of thestile l0 in order that the ladder may be maintained level when set up.Inward axial movement of the shaft 35 will cause the collar 4D to engagethe recess 39.

so as to lock the leg member 20 and its associated parts inany desiredadjusted position. In order to releasably retain the shaft 35 and itsassociated parts in their locked position as shown in Figure 3, abearing block 45 is connected through the bolts 45 to the inner side ofone of the flanges I4 of the channel member I2 (Fig. 3). The block 45has an opening in which is mounted a bushing 41 for receiving the shaft35. The block 45 also is provided with a transverse opening 43 (Fig. 8)through which extends a plunger 49 having a removable head 59 and isprovided at its inner end with a laterally extending portion or arm 5|arranged to fit into a circumferential groove 52 in the shaft 35 (Fig.9) so as to prevent longitudinal movement of the shaft. The arm 5| isreleased from the groove 52 by depression of the plunger 49 so that theshaft may be moved outwardly to the position shown in Figure 10, torelease the collar or clutch member from the boss 31. A spring 53 isconnected as at 53 to the block 43 and engages the arm 5| so asyieldably to maintain the same in contact with the shaft 35. The innerfree end of the arm 5| has a stud or pin 54 that slides within acomplementary formed recess 55 in the bearing block so as to insure theplunger 49 and its associated parts being maintained in proper position.The inner surface of the stile |2 adjacent the transverse shaft 35 iscut out as at 56 (Fig. 6) so that the leg attachment may be convenientlyconnected to the stile and rmly secured thereto by the spaced retainingbolts I5.

Preferably each of the lower end portions of the stiles |2 is providedwith one of the attaching members. It will be seen that when itisdesired to use the ladder on an uneven surface such as when associatedwith a stair or a sudden drop in the ground, that upon releasing theshaft 35 from its locked engagement with the boss 36 by depressing theplunger 49, the shaft 35 may be moved axially outward from the positionshown in Figure 9 to that shown in Figure 10 without disturbing theengagement of the pinion 4| with the teeth 23 of the ribV 2|. Upon thisaxial outward movement of the shaft 35, the collar 49 is moved out ofengagement with its associated recess 39 to allow free rotatablemovement of the shaft 35 in order to move the leg member 20 and the foot21 either outwardly 0r inwardly so as to properly adjust the stile |2 inorder to maintain the ladder level. When the leg member 20 is moved tothe desired adjusted position it is maintained locked in this positionby moving the shaft 35 inwardly so as to cause the clutch or collar 4|)to again engage the recess 39, to prevent rotation of the shaft 35 andits associated parts.

In the modified form of the invention shown in Figure 11, the operatingshaft 35 and its associated parts are substantially similar to the partspreviously described, with the exception that instead of forming alocking member on the shaft, the pinion 4| is arranged to co-act withthe teeth 51 of a serrated plate 58 that is fastened to the plate I6adjacent the side of the rib 24. The inner end portion 59 of the shaft35 is slidable in a boss 60 which may be connected to one of the sideflanges I4 by the threaded bolts 6| and their co-acting threaded nuts62. As shown in full lines in Figure 11 the shaft 35 is moved inwardlyso that the pinion 4| meshes with the teeth 51 for locking the legmember 20 in a fixed position. Upon axial movement of the handle 43 tothe dotted line position, the pinion 4| is moved laterally out of meshwith the teeth 51 on the plate 58 so that rotation of the shaft 35 movesthe leg member 20 and its associated parts relative to the'stile inorderv that the ladder will assume *a level' "positionl irrespective ofthe unevennessof the ground on which lt is supported. --Thuspitrwillbefseenthat simple, efficient and positive means are provided inthe-form of an attachment which may be readilyconnected to either orboth the stiles -l of a ladder and 'which whenA the'- parts areset up,insures the ladder being firmly maintained in a iixed position.Additionally, the discs '21 and 28 which constitute the foot member maywhen the teeth become dull or worn be rotated to present new teeth tobe-engagedwiththe ground, by the simple expedientv of loosening the boltso as to allowthe disc 21 to be moved away from lockingengagement withthe pointed end 32 of therack" bar 2| so as to rotate the discs andpresent a new set of teeth tb beengaged with the ground. The discs arethen moved so that theypointed end 32 of the rack bar 2| again engagesthe sides of the teeth 3| of the Idisc 21 so as to prevent' rotationthereof. The bolt 25 is then clamped by the nut 29 so as to main-l tainthe discs 21 andl 28Nintheir proper fixed position. `While the discs 21and'28 are shown separate they could be made in one piece. Additonally,the pointed end 32 of the rack bar while shown arranged to engage onlythe teeth of the disc 21 may be of sufficient Width to engage the teethin the disc 28 so as to prevent rotation of both of these parts when itis'desired to lock the discs or Wheels.

It will be understood that the forms of the vinvention shown are merelyillustrative of preferred embodiments and that such changes may be madeas fall within the purview of one skilled in the art without departingfrom the spirit of the invention and the scope of the following claims.

I claim:

1. In combination with a ladder stile, an extensible attachmentincluding a channel shape member engaging the outer side of the stileand having spaced arms engaging the front and rear sides thereof, a legmember slidably mounted within the channel member, a rack bar connectedto the leg member and extending longitudinally thereof, a rotatable andaxially movable operating shaft extending transversely through thechannel member, said shaft having a pinion constantly in mesh with saidrack bar, a tubular boss connected to one arm of the channel member andarranged to slidably receive the operating shaft, said boss having meansco-acting with complementary means on said shaft for locking the shaftand the leg member in a fixed position, and means for moving said shaftinto and out of its locked position.

2. In combination with a ladder stile, an extensible attachmentincluding a channel member having a base engaging the outer side of thestile and spaced arms engaging the front and rear sides of the stile, aplate secured within said channel member and spaced from the base toprovide a passage, said plate having a longitudinally extending outwardoffset housing provided with a cut-out portion, a rack bar on said legmember and positioned Within said housing, an operating shaft extendingtransversely of the channel member and having a pinion extending throughthe cut-out portion of said housing and meshing with said rack bar, saidoperating shaft being rotatably and slidably mounted on the spaced armsof the channel member, and locking means associated with said pinion forpreventing rotationof the shaft and'movement of the leg member, andmeans for moving the pinion linto and out of engagement with the lockingmeans.

1 3. In combination with a ladder stile, an extensible attachmentincluding a channel member having a base engaging the outer side of thestile and spaced arms engaging the front and lrear sides of the stile, aplate secured within said channel member and spaced from the base toprovide a passage, said plate having a longitudinally extending outwardoffset housing provided with a cut-out'portion, a rack bar on said legmember and positioned within said'housing, an operating shaft extendingtransversely 'of-the channel member and havingv a pinion extendingthrough the cut-out portion of said housing and meshing with said rackbar, a tubular boss connected to an arm of the channel 'member Aandarranged to slidably receive said operating shaft, said boss havingmeans co-acting with complementary means on said shaft for locking theshaft and the' leg member in a fixed position, and means for moving saidshaft into and out of'its locked position.

4.-. In combination'with a ladder stile,v an extensible attachmentincluding a channel mem-y ber having a base engaging the outer side ofthe stile and spaced arms engaging the front and rear sides of thestile, a plate secured within said channel member and spaced from thebase to provide a passage, said plate having a longitudinally extendingoutward offset housing provided with a cut-out portion, a rack bar onsaid leg member and positioned within said housing, an operating shaftextending transversely of the channel member and having a pinionextending through the cut-out portion of said housing and meshing withsaid rack bar, a tubular boss connected to an arm of the channel memberand arranged to slidably receive said operating shaft, clutch means onsaid boss co-acting with complementary clutch means on said shaft forpreventing rotation of the shaft and the movement of the leg member, andmeans for moving the clutch means into and out of locking engagement.

5. In combination with a ladder stile, an extensible attachmentincluding a channel member having a base engaging the outer side of thestile and spaced arms engaging the front and rear sides of the stile, aplate secured within said channel member and spaced from the base toprovide a passage, said plate having a longitudinally extending outwardoffset housing provided With a cut-away portion, a rack bar on said legmember and pisitioned within said housing, an operating shaft extendingtransversely of the channel member and having a pinion extending throughthe cut-out portion of said housing and meshing with said rack bar, saidoperating shaft being rotatably and slidably mounted on the spaced armsof the channel member, and locking means associated with said pinion forpreventing rotation of the shaft and movement of the leg member, andmeans for moving the pinion into and out of engagement with the lockingmeans, and a serrated platev connected to the channel member adjacentthe rack bar, said pinion upon axial movement of the operating shaftbeing moved into and out of locking engagement With said plate toprevent movement of the leg member.

6. In combination with a ladder stile, an extensible attachmentincluding a channel member having a base engaging the outer side of theAstile and spaced arms engaging .the `iront and rear sides of the stile,-a plate secured Within said channel member .and spaced from .the :baseto provide ya passage, said y,plate .having a iongitudinally extendingoutward offset housing provided with a out-out portion, a ,rack bar onL.sa-id -leg .member and :positioned within said housing, vanoperating-shaft extending transversely of the channel member and .having.a `pinion extending through the out-out portion of .said housing andmeshing with said .raek bar, and releasable means engaging said shaftfor y*preventing vaxial movement thereof.

7. In combination with a ladder stile, an .extensible attachmentincluding a lchannel member having a fb'ase `Ieng-aging the .outer sidelof .the .stile and spaced arms "engaging the front and rear sides ofthe stile, a plate secured within said lchan-nel .member 'and :spaced.from the base to provide a passage, said plate having .falongitudinally vextending outward offset housing ;pr.ovided with .acnt-out portion, fa y.rack .bar on said leg member .and positionedWithin said `housing, an operating shaft extending transversely of the.channel member and having a `pinion eX- tending through v.the cut-outportion of said housing and-meshing withsaid rack sbar, spaced bearingmembers .connected to .the .arms .of said lchannel member :for slidablyreceiving said shaft, a movable plunger 'extendingzoutwa-rdly from oneof the bearing 'members .and yieldably connected to said plunger 'andarranged t0 engage said fshaft iorpreventing Iaxial `movement thereof.

ROBERT C. .MAYBERRY..

REFERENCES CITED The V:Following references Aare .of record in fthe fileof fpatenft:

'UNITED STATES .PATENTS Number lName Date 742,288 Charles Oet..27, 11963.1,293,066 lFaulkner Feb. .4, 191:9 1,'4605359 Maclear .June 26, '.19231,651,863 .Baur Dee. 6, 11927 .1,897,840 Green Feb. 14, 1933 .2,451,113Ozols Out. 12, 1948 FOREIGN Number Country Date Y1,730 Great Britain:18.72

